Electric switch.



,724; PATENTED JAN, 6, 1903. W. R. THOMPSON.

ELECTRIC SWITCH.

APPLICATION FILED MAY 28v 1902.

, N0 MODEL.

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UNITED STATES ATsNT \VlLLlAM R. THOMPSON, OF NORWALK, CONNECTICUT, ASSIGNOR OF ONE- HALF TO GEORGE N. MCKIBBIN, OF NORW'ALK, CONNECTICUT.

ELECTRIC SWITCH. V

SPECIFICATION forming 'part Of Letters Patent N 0. 717.724, dated- 311113113 1903 Application filed May 28, 1902. Serial No. 109,263. (No model.)

9 all whom it may concern:

Beit known that 1, WILLIAM R. THOMPSON, a citizen of the United States, residing at Norwalk, Connecticut, have invented certain new and useful Improvements in Electric Switches, of which the following is a clear, full, and exact description.

My invention relates to an electric switch; and my object is to improve the construction [0 of the same and at the same time to provide a switch which is simple and compact and which will insure good electrical contact between the terminals.

My invention will be defined in the claims.

In the drawings showing the preferred embodiment of my invention, Figure 1 shows a top plan view with a diagram of electrical connections; Fig. 2, a bottom plan view, and

Fig. 3 a central vertical section of Fig. 1.

2o 1 is a base of insulating material-such, for example, as hard rubber. In the bottom of the base I have formed a recess, preferably in the shape of an elongated channel.

2 is a slot, preferably elongated, as shown,

2 5 which extends through the base and communicates with the recess. 3 and 4C are electrical contact-terminals at either side of said slot, and 6 is a third terminal, which may be metallic plates let into depressions in the bot- 0 tom of said recess, so that they are flush with the bottom of said recess, as shown in Fig. 3, andinsulated from each other. 5 is a switchterminal which may be in the form of a bowspring located in said recess with its ends 3 5 pressing against the bottom of said recess and adapted to bridge either of said side terminals and the middle terminal 6. 7 is a stud attached to said spring and extending through said slot 2, by which said spring may be shifted 0 from the position shown in Fig. 1 to that shown in Figs. 2 and 3. This stud preferably has a finger piece or button 8, whose base forms a flange extending laterally beyond said slot,

as shown in dotted lines in Fig. 1, for hold- 5 ing the spring under tension. The ends of the spring press firmly against the contactplates, and as the spring is shifted from one position to the other they rub overthe plates and insure a good electrical connection. Bindvided on each of the terminal plates, if desired.

As all the electrical connections are in the embodiment illustrated located above the bottom of the base, the switch may be attached to 5 5 any structure without danger of short-circuiting. Itis also simple, compact, and efficient in its action. It is particularly useful in connection with a sparking device of an explosive-engine where it is desirable to start the engine by connecting the sparking device with a battery and then switching it into circuit with a dynamo. I have illustrated such an arrangement in diagram in Fig. 1, in which 12 indicates a sparking device, 13 a battery, and 14 a dynamo.

I am aware that many variations from the foregoing construction may be made without departing from my invention as claimed, and I therefore do not desire to be limited to the embodiment herein illustrated and described.

What I claim is 1. In an electric switch in combination, a base of insulating material having a recess in the bottom of said base and aslot through said base communicating with said recess, a metallic contact-terminal carried by said base at one side of said slot, a second contact-terminal, and a metallic spring located in said recess and adapted to bridge said terminals, and a'projection through said slot to shift said spring.

2. In an electric switch in combination, a base of insulating material having a recess in the bottom of said base and a slot through said base communicating with said recess, a metallic contact-terminal carried by said base at each side of said slot, a third contact-terminal between the same, a metallic spring located in said recess and adapted to bridge 0 either of said side terminals and said middle terminal, and a projection through said slot to shift said spring.

3. In an electric switch in combination, a base of insulating material having a recess 5 in the bottom of said base and an elongated slot through said base communicating with said recess, a metallic contact-terminal carried by said base at each side of said slot, a

50 ing-posts or screws 9, 10, and 11 may be prothird contact-terminal between the same, a too metallic spring slidable in said recess and adapted to bridge either of said side terminals and said middle terminal, and a projection through said slot and attached to said spring to shift said spring.

4. In an electric switch in combination, a base of insulating material having a recess in the bottom of said base and an elongated slot through said base communicating with said recess, a metallic contact-terminal carried by said base at each side of said slot, a third contact-terminal between the same, a metallic spring slidable in said recess and adapted to bridge either of said side terminals and said middle terminal, and a projection through said slot to shift said spring, said projection being attached to said spring and having a flange projecting laterally beyond said slot to hold said spring under tens10n.

5. In an electric switch in combination, a base of insulating material having a recess in the bottom of said base and an elongated slot through said base communicating with said recess, a metallic contact-terminal carried by said base at each side of said slot, a third contact-terminal between the same, said side terminals being let into the material of said base flush with the bottom of said recess, a metallic bow-spring pressing with its ends against the bottom of said recess and slidable in said recess and adapted to bridge either of said side terminals and said middle terminal, and a projection through said slot to shift said spring, said projection being attached to said spring and supplied with means for holding said spring under tension.

Signed at South Norwalk, Connecticut, this 16th day of April, 1902.

WILLIAM R. THOMPSON.

Witnesses:

BESSIE T. MILLS, LoUIs S. BEERs. 

